# Tagged Questions

Questions about the apparent displacement of a celestial body with respect to its background when observed along two different lines of sight.

68 views

### A quick (elementary) check on arsecond conversion to sky distance in parsecs

I just wanted to double check I had something correct. If an object, say a nebula, is measured to roughly have a diameter or extent of, say, 250 arcseconds, would its diameter in parsec simply ...
27 views

### How to Calculate Parallax Angle [duplicate]

I understand that parallax "is a displacement or difference in the apparent position of an object viewed along two different lines of sight" - Wikipedia. So, when calculating the distance from the ...
81 views

### Measuring star distance by parallax using a small telescope

I was wondering if it's possible to measure star distance using parallax at home with a small telescope (Something like a 3-inch reflector)? Or is this not really practical?
274 views

### How would parallax affect an object at 200-1000 AU (for example, the 9th planet)?

We know from this question that an object is hypothesized to be at between 200-1000 AU that is large enough to detect, known now as the 9th planet. It should move about 40 arcseconds per year. It ...
78 views

### When is Gamma Draconis closest to the zenith in London on April 4th

I am reading Roobert Hooke's paper An attempt to prove the motion of the earth from observations (1674, faksimile). Hooke writes The principal dayes of doing which will be about the 4 of April, ...
856 views

### How does a telescope measure parallax angle?

I know how stars' distances are measured by using parallax, but I want to know how the actual telescope measures the parallax angle. Any helpful links/ explanations are needed.